Abstract: An insulated glass unit comprises two sheets of glass separated by an aluminum spacer, a thermosetting resin sealant such as a polysulphide or polyurethane sealant or a hot melt butyl sealant being applied around the edges of the unit to seal the sheets together. The spacer is connected by corner keys made of aluminum tape. Curing or melt-bonding of the sealant is accelerated by the application of microwave energy, suitably by passing the unit through a tunnel with microwave generators on each side thereof. The unit passes through the tunnel on a conveyor held upright by pinch chains. The conveyor and pinch chains are made of a nonpolar material such as polypropylene.

Abstract: A process for the manufacture of a partially cured polysulphide composition is provided, the curing of which is completed upon exposure of the composition to atmospheric moisture. The process comprises mixing a prepolymer with a water activatable curing agent and subjecting the composition to a partial cure with water. The reaction is then stopped by rapid dehydration after the initial induction stage of the reaction prior to the rapid increase in the viscosity of the composition. Curing of the composition is then completed by exposing the composition to atmospheric moisture.

Abstract: Polysulfide sheeting is prepared by mixing a curable polysulfide oligomer or polymer, carbon black, and manganese dioxide as a hardening catalyst; forming the composition into a sheet; and curing the sheet at an elevated temperature. The sheeting has unusually high short-term heat resistance, so it will not lose its watertightness when coated with hot-laid asphalt at 240.degree. C. It has better resistance to ultraviolet light than conventional polysulfide sheeting, and good penetration and compression set resistance. The sheeting can be laminated to a reinforcing layer, if desired. A continuous waterproofing layer can be formed by laying pieces of the sheeting in overlapping relation, placing an uncured polysulfide rope between the overlapping edges of adjacent pieces of sheeting, and curing the rope, thus joining the pieces to form an integral sheet. Such waterproof layers can be incorporated into paving for bridges, roofs, and other structures.

Abstract: Stable liquid adduct compositons are prepared by an addition reaction between epoxy-terminated polymers and mercaptan-terminated polymers. One of the polymers is in stoichiometric excess so that the composition has free epoxy or mercaptan functional groups. The liquid polymer composition can be stored for long periods before curing with a curing agent reactive with the free functional groups.